2-bromopyridine

Structural formula
General
Surname	2-bromopyridine
other names	o -bromopyridine; ortho- bromopyridine;
Molecular formula	C 5 H 4 BrN
Brief description	colorless to yellowish liquid with a pyridine-like odor
External identifiers / databases
EC number	203-641-6
ECHA InfoCard	100.003.311
PubChem	7973
Wikidata	Q209317
properties
Molar mass	158.00 g mol −1
Physical state	liquid
density	1.62 g cm −3 (20 ° C)
Melting point	−40.1 ° C
boiling point	193 ° C
Vapor pressure	1.02 h Pa (25 ° C)
solubility	moderate in water (20 g l −1 at 20 ° C)
Refractive index	1.5734 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger
H and P phrases	H: 301-310-315-319-335
	P: 280-302 + 352-304 + 340-305 + 351 + 338
Toxicological data	92 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

2-Bromopyridine is an organic compound that belongs to the heterocycles (more precisely: heteroaromatic compounds ). It consists of a pyridine ring, which is substituted in the 2-position with bromine .

presentation

In general, common electrophilic aromatic substitutions on pyridine are not possible or only possible with poor yield. Furthermore, pyridine would preferentially be substituted in the 3-position and 2-bromopyridine would only arise as a by-product. However, 2-bromopyridine can be prepared by reacting with molecular bromine in the presence of catalytic amounts of palladium (II) chloride .

use

2-bromopyridine and 2-chloropyridine can be converted to 2,2'-bipyridine in a Ullmann coupling , for which copper dust is used . It can also be used for the synthesis of 2,4'-bipyridine . To this end , it can be reacted with 4-bromopyridine in a Negishi coupling . For this purpose, 2-bromopyridine is first lithiated with n- butyllithium and transmetallated to zinc organyl with the addition of zinc chloride . A palladium complex with triphenylphosphine ligands is used as the coupling catalyst .

By lithiation , 2-bromopyridine can be converted into an organolithium compound , which serves as a starting compound for other pyridine derivatives that are not directly accessible.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Data sheet 2-bromopyridine (PDF) from Merck , accessed on March 20, 2011.
↑ ^a ^b ^c David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-70.
^ ^A ^b J. A. Joules, K. Mills: Heterocyclic Chemistry , 2000 , 4th edition, Blackwell Science, Oxford, ISBN 0-632-05453-0 , pp. 77-81.
^ FH Burstall: Researches on the polypyridyls , in: J. Chem. Soc. , 1938 , pp. 1662-1671; doi : 10.1039 / JR9380001662 .
^ DR Sidler, N. Barta, W. Li, E. Hu, L. Matty, N. Ikemoto, JS Campbell, M. Chartrain, K. Gbewonyo, R. Boyd, EG Corley, RG Ball, RD Larsen, PJ Reider , Paul J: Efficient synthesis of the optically active dihydropyrimidinone of a potent α _1A -selective adrenoceptor antagonist. In: Canadian Journal of Chemistry . 80 (6), 2002, pp. 646-652, doi : 10.1139 / v02-079 .

[merck-1] ↑ ^a ^b ^c ^d ^e ^f ^g Data sheet 2-bromopyridine (PDF) from Merck , accessed on March 20, 2011.

[CRC-2] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-70.

[joules-3] A ^b J. A. Joules, K. Mills: Heterocyclic Chemistry , 2000 , 4th edition, Blackwell Science, Oxford, ISBN 0-632-05453-0 , pp. 77-81.

[4] FH Burstall: Researches on the polypyridyls , in: J. Chem. Soc. , 1938 , pp. 1662-1671; doi : 10.1039 / JR9380001662 .

[5] DR Sidler, N. Barta, W. Li, E. Hu, L. Matty, N. Ikemoto, JS Campbell, M. Chartrain, K. Gbewonyo, R. Boyd, EG Corley, RG Ball, RD Larsen, PJ Reider , Paul J: Efficient synthesis of the optically active dihydropyrimidinone of a potent α _1A -selective adrenoceptor antagonist. In: Canadian Journal of Chemistry . 80 (6), 2002, pp. 646-652, doi : 10.1139 / v02-079 .